Thermometer for melting point apparatus



W. O. GEYER THERMOMETER FOR MELTING POINT APPARATUS May 4, 1937.

Filed Aug. 31', 1935 I NVENTOR zllzam 0 6'9 g; Y

46 ATTORNEY \\1 J DLLLLLLLII J:

Patented May 4, 1937 UNITED STATES PATENT FFICE THERMOMETER FOR MELTINGPOINT APPARATUS Claims.

This invention relates to chemical apparatus and more particularly toapparatus for the determination of the melting points of materials. Oneof the objects of the present invention is to provide apparatus whereina plurality of melting point determinations may be made at the sametime. v Another object is to provide means to support and sustain aplurality of samples for melting point determinations in such apparatus.

Still another object of this invention is to provide an improved meansand apparatus for mak ing melting point determinations.

Other objects and advantages will be apparent as the invention is morefully disclosed.

In accordance with the above objects I have devised a melting pointapparatus which is provided with means to support and sustain aplurality of samples within the apparatus in such position relative to athermometer that melting point determinations may be made on theplurality of samples at one and the same time.

Before further disclosing the present invention reference should be madeto the accompanying drawing wherein Fig. 1 illustrates one type ofmelting point apparatus including the improvement of the presentinvention;

Fig. 2 illustrates a second type melting point apparatus including amodification of the present invention;

Fig. 3 is an enlarged View of the thermometer and material supportingmeans of the present invention;

Fig. 4 is an enlarged view of a modification of the same;

Fig. 5 is a view along plane 55 of Fig. 3;

Fig. 6 is a View along plane 6-6 of Fig. 3;

Fig. 7 is a view along plane 1-! of Fig. 4.;

Fig. 8 is an enlarged section of a modification of the presentinvention.

Referring to Figs. 1 and 3, the melting point apparatus indicatedcomprises a flask I having an elongated neck 2 sealed from theatmosphere to the outer periphery of re-entrant tube 3, the

bottom of tube 3 extending to the approximate center of flask I.Stoppered opening means 4 and 5 are provided in neck 2 to permit theintroduction of suitable fluid 6, such as water, oil, waxes or sulfuricacid, in flask l.

Re-entrant tube 3 is provided with a stopper 1 (preferably of cork)through which extends thermometer 8, the bulb end 9 of said thermometerbeing located adjacent the bottom of re-entrant tube 3. Means areprovided to sustain and support at least one and preferably a pluralityof samples of material H to be subjected to melting pointdeterminations, about the bulb end 9 of thermometer 8 in determinedspaced relationship 0 to the said end 9.

It is usual in making melting point determinations to dispose thematerial IT in tube l 0 of relatively small internal diameter and todispose the same in the bottom of re-entrant tube 3 with the bulb end 9of thermometer 8 located adjacent the material.

There are obvious difficulties of inserting and removing the tube IDfrom tube 3. To overcome this it has been customary to temporarilysecure the tube Ill to thermometer 8 as by tying the same thereto withstring, wire or rubber band. These expediencies while overcoming themechanical difiiculty of inserting and removing the tube Ill haveintroduced errors in melting point determinations such that checkresults on successive portions of the same material are difficult toobtain. Moreover, in some instances the temporary securing materialoften becomes charred or otherwise destroyed during heating and tube l0falls off and this often interferes with the determination.

I overcome this difficulty by providing the bulb end 9 of thermometer 8with means H and I2 (Fig. 3) to support and sustain a plurality of tubesl0 about the outer periphery of the said bulb end in determined spacedrelationship to the said end. The heat radiated by fluid 6 through thewalls of tube 3 upon the material in tube l0 strikes each tube l9uniformly. As bulb end 9 is disposed at approximately the axial centerof flask I it also is uniformly heated from all sides. Accordingly eachof the tubes Ii] when filled with the same material will meltsimultaneously and the thermometer reading will be in a definite fixedratio to the true melting temperature depending upon the spacing of thetubes ID from the outer peripheral surface of the thermometer. By makingthis spacing as small as economically practical the recorded temperaturemay be brought in relatively close agreement with the true temperatureof melting and any difference therebetween will remain a constant factorwhich may be calibrated and allowed for.

This uniformity in spacing of tube H] from the bulb end 9 of thethermometer 8 heretofore has not been accorded proper consideration inmelting point apparatus. I obtain this as indicated in Figs. 3, 5, and 6by providing the peripheral surface of thermometer 8 at a suitabledistance remote from the bulb end, with a plurality of annularextensions ll having a center opening slightly larger than the externaldiameter of tube 10. Bulb end 9 of thermometer 8 is provided with aplurality of extensions l2 having recesses l3. The axial centers ofannular extensions H and recesses 13 of extensions l2 are aligned in thesame plane parallel to the longitudinal axis of thermometer 8 and asclose to the surface of thermometer 8 as is economically practical.

material in the bottom of tube In.

Preferably annular extensions H and recessed extensions l2 are comprisedof glass of the same composition as employed in thermometer 8 to avoidunequal expansion and contraction and resultant stresses and strains,and are fused or.

otherwise made integral With the peripheral surface of thermometer 8.

As a specific embodiment of the present invention the outside diameterof thermometer 8 above the bulb end 9 approximates 7 millimeters. Theoutside diameter of tube It approximates 2 millimeters. The length oftube I ll approximates millimeters;

I dispose annular extensions ll about the peripheral surface ofthermometer 8 at a distance about 5.4 millimeters from the tip end ofbulb 9 with the axial center about 6 millimeters away from the surface.With two annular extensions II on opposite sides of thermometer 8 theover all diameter of the thermometer approximates 18 millimeters.

Extensions [2 are built out similarly from the bottom of bulb 9, thusbringing the longitudinal center of tube l K! disposed in any alignedextensions and [2 to Within 3 millimeters of the bulb end 9 of thethermometer 8. This is just about as close as the tube lil may bedisposed to bulb end 9 and still maintain its longitudinal axis parallelto the longitudinal axis of the thermometer 8. The depth of the recessesin extension l2 may vary widely Without departure from the presentinvention. In determining melting points of materials in this type ofapparatus it is customary to observe the melting point of the It isessential therefore to maintain the tip end of tube Ill in such positionthat the first indication of melting of the material in the end may beobserved. As indicated in Figs. 1 and 3 this may be accomplished byproviding very shallow recesses in extension !2. Alternatively asindicated in Fig. 8 a deeper recess may be employed when the tube M isprovided with an extension 15 adapted to be received in the deeperrecess leaving the material level above the recess, if desired.

In the modification illustrated in Figs. 2, i, and '7, the materialsupporting and sustaining means is altered to provide a flat disc l2 inplace of the plurality of extensions l2 and two sets of annularextensions ll and I! are provided to insure the retention of tubes I Bin parallel spaced relationship with the thermometer 8.

The modif ed flask l indicated in Fig. 2 is not a part of the presentinvention except when used in combination with the thermometer 8 andtube [0 Supporting and sustaining means H and I2 (I I and 12) asheretofore described. In such modified flask l the thermometer 8 isimmersed directly in fluid 6 with the open ends of tubes [0 extendingabove the level of fiuid 6. Burner I4 is utilized to heat fluid 5 inchannel E5 of flask I.

While I have herein above disclosed that a plurality of tube l0supporting means H and i2 are desirable, it is apparent that I mayprovide one or more of such means up to as many as may be disposed aboutthe peripheral surface of thermometer 8. Other modifications andadaptations of the present invention and of the supporting andsustaining means H and I2 (H and i2) will be apparent to one skilled inthe art but all such are contemplated as may fall within the scope ofthe following claims.

What I claim is:-

1. A thermometer for melting point apparatus, the bulb end of saidthermometer being provided with means to sustain and support a portionof the material to be tested in determined spaced relationship to saidbulb end, said means comprising an annular extension and a recessedextension attached to the surface of said thermometer, the annularextension being disposed at spaced distance from said end and therecessed extension being attached to said end, the axial center of theannular opening of one being aligned with the axial center of the recessof the other in a plane parallel to the longitudinal axis of saidthermometer, and a tubular member for retaining the sample to be testedadapted to be received in said annular opening and to rest in saidrecess with the material in the bottom of said tubular member in fullview.

2. A thermometer for melting point apparatus, the bulb end of saidthermometer being provided with means to support and sustain at leastone tubular member in axial parallel spaced relationship with said end,said means comprising a plurality of annular extensions disposed aboutthe periphery of said thermometer a distance from said bulb end, theannular openings of said extensions at least approximating the outsidediameter of said tubular member, and means integral with the saidbulbend to receive and retain the bottom of said tubular member whendisposed within said annular extension.

3. A thermometer for melting point apparatus, the bulb end of saidthermometer being provided with means to support and sustain at leastone tubular member in axial parallel spaced relationship with said end,said means comprising a plurality of annular extensions disposed aboutthe periphery of said thermometer a distance from said bulb end, theannular openings of said extensions at least approximating the outsidediameter of said tubular member, and a plurality of recessed extensionsintegral with the bottom of said bulb end aligned with said! annularextensions with the recess in a position adapted to receive the bottomof said tubular member when disposed within said annular extension andto retain said tubular member in determined spaced relation to said bulbend.

i. A thermometer for melting point apparatus, the bulb end of saidthermometer being provided with means to support and sustain at leastone tubular member in axial parallel spaced relationship with said end,said means comprising a plurality of annular extensions disposed aboutthe periphery of said thermometer a distance from said bulb end, theannular openings of said extensions at least approximating the outsidediameter of said tubular member, and a disc extension integral with thebottomo-f said bulb end with a flat surface in position to receive thebottom of said tubular member when disposed within said annularextension, thereby retaining the said tube in spaced relation to saidbulb end.

5. A thermometer for melting point apparatus, the bulb end of saidthermometer being provided with two sets of annular extensions in spacedalignment about the periphery of the said thermometer a spaced distancefrom the bulb end of the thermometer and a fiat disc extension integralwith the said bulb end the diameter of said disc extension being atleast equal to the overall diameter of said thermometer and said annularextensions.

WILLIAM O. GEYER.

